A brief acoustic set in the middle of the show had Nick Carter again pleading with the crowd to give the new record a chance. After going into “Madeleine” with a voice crack on the first note, the whole group laughed at him, even while singing. Carter, beet red, finished the song by saying, “Well. Now you don’t want to buy the record.”

Carter also marveled at a “boy band playing instruments” and nodded to their collective realization that, to stay afloat, they all needed to learn to play because they’d eventually be too old to dance.

A vignette shown during a costume change previewed “Backstreet Boys — The Movie,” tentatively due later this year. For all the eye-rolling that revelation may have induced, the trailer was full of candid interview soundbites.

“Nobody tells you what to do when you get to the top,” says crowd favorite Brian Littrell.

“All we’re doing is keeping our heads above water,” says Carter.

The show closers were a few of BSB’s most memorable tracks and accidentally hilarious performances, including the iconic “Everybody (Backstreet’s Back).” BSB used much of the original choreography, and Carter made a point to find a camera to point at his groin on every mention of the word “sexual.” Behind him, a fan who paid for a VIP pit ticket held a handmade sign that read: “Nick: I’m not jailbait anymore.”

That’s…kind of weird, admittedly. There were plenty of “oh no” moments like that, but it all had the strange and unexpected feel of being in good fun. The whole ordeal seemed less an attempt to hold onto the past and more a celebration of it. These gentlemen, more dapper than ever even when randomly and frequently sleeveless throughout the show, still sent sections of the crowd into flurries of shrieks and hugs with a mere wink or wave, but without the inherent drama or tragedy of preteen idol love.

Even though one might expect it to seem forced, how it didn’t feel is like ’N Sync’s halfhearted 2013 reunion performance at the MTV Video Music Awards, or like Beyonce throwing the rest of Destiny’s Child a televised bone at last year’s Super Bowl. Maybe (and ironically) the Backstreet Boys are lucky in that they have no clear frontrunner in talent or looks, no runaway superstar. There is no MJ, no Timberlake ... not even a Nick Jonas among their ranks to shake up the hierarchy.

They appeared, surprisingly and simply, to be a group of longtime friends and coworkers who still happen to enjoy what they do with impressive humility and only a modicum of embarrassment about their history, which — apparentl y— is a pretty good formula for longevity.